Flowrate control valve for powder and granular material

ABSTRACT

An edge plate  11  of prescribed height is provided around three sides except a free end side of a swinging plate  5  that can close the lower end of an ore fines inlet pipe  2  which is tilted at a prescribed angle. By the edge plate  11  of prescribed height, when the swinging plate  5  is opened, the ore fines are allowed to flow out only from the free end side of the swinging plate  5  provided that the opening height is held within the height of the edge plate  11 , and an accurate flow control of ore fines can thus be achieved.

TECHNICAL FIELD

The present invention relates to a flow control valve for controlling aflow rate of ore fines flowing from an upper part to a lower part of apipe line.

BACKGROUND ART

Conventionally, when transferring the ore fines of iron carbide, cementclinker, coal, iron ore or the like, it has often been practiced tocontrol the flow rate of ore fines during transferring.

One known example of such a flow control valve for ore fines is a valve50 rn such as shown in the longitudinally sectional view of FIG. 5.However, since this valve 50 operates by just opening and closing aswinging plate 51, it is not possible to stably and accurately controlthe quantity of ore fines because the ore fines flow from an inlet pipe52 through not only the lower end of the swinging plate 51 but also theside edges of the plate, and the valve 50 is therefore not suitable foruse as a flow control valve for accurately controlling the flow rate.

Another known example of such a flow control valve for ore fines is arotary valve 60 such as shown in the longitudinally sectional view ofFIG. 6. However, since this valve 60 has a rotor 61 which is rotating atall times, the ceaseless rotation accelerates the wear of rotating partsand shortens the lifetime. Furthermore, in case of controlling the flowrate, the rotational speed of the rotor 61 must be controlled in avariable manner, which increases the equipment cost.

To resolve these problems, the applicant of the present invention haspreviously filed a patent application for an invention which isdisclosed in Japanese unexamined Patent Application No. 7-223698. Avalve 70 for ore fines disclosed in the above patent applicationcomprises, as shown in the longitudinally sectional view of FIG. 7, acasing 71 and a rotatable valve body 72 built into the casing 71, inwhich the casing 71 has a sideway inlet opening 73 continuing from apipe installed thereon and a downward outlet opening 74 communicatingwith the inlet opening 73, and the valve body 72 is comprised of a firstopening 75 connected in slidably rotatable fashion to the inlet opening73 and a second opening 76 communicating with the first opening 75 so asto face the outlet opening 74.

By rotating the valve body 72 using driving means, the ore finespositioned at the inlet opening 73 is allowed to flow through the firstopening 75 to the outlet opening 74 via the second opening 76, therotation angle of the valve body 72 being controlled so that aprescribed quantity of ore fines can be discharged.

However, since the valve 70 for ore fines is designed to discharge acontrolled quantity of ore fines by applying the angle of repose of theore fines, the maximum attainable flow rate is small for the diameter ofthe inlet pipe, requiring a larger size valve for the required quantityof discharge. Furthermore, the structure of the valve becomes complex.Increased valve size and complex structure lead to an increase in valvecost. There is also the possibility that the ore fines may enter betweensliding faces.

DISCLOSURE OF INVENTION

To resolve the above problem, according to the present invention, thereis provided a flow control valve for ore fines comprising an ore finesinlet pipe whose lower end is cut at a prescribed angle and a swingingplate installed in swingable fashion to control the flow rate of orefines by controlling the opening degree between the swinging plate andthe lower end of the ore fines inlet pipe, wherein the ore fines inletpipe is installed with its axis center tilted at an angle greater thanthe angle of repose of the ore fines, the swinging plate, when it keepscontact with the lower end of the ore fines inlet pipe, makes an acuteangle with the axis center of the ore fines inlet pipe and the swingingplate is supported at an upper end thereof so that the support portionis positioned above the lower end opening of the ore fines inlet pipe,and an edge plate of prescribed height is provided around three sidesexcept a free end side of the surface of the swinging plate which closesthe lower end of the ore fines inlet pipe.

As described above, since the axis center of the ore fines inlet pipe istilted at an angle greater than the angle of repose of the ore fines,the flow of ore fines can be stabilized at a slower velocity than wouldbe in the case if the axis center were held in vertical position, andfurther, since the edge plate of prescribed height is provided aroundthe three sides except the free end side of the surface of the swingingplate which closes the lower end of the ore fines inlet pipe, when theswinging plate is opened, the ore fines are allowed to flow out onlyfrom the free end side of the swinging plate within the height of theedge plate. Accordingly, the flow rate of ore fines can be controlled byrestricting the flowing section of ore fines within a predeterminedrectangular section. Thus, since an accurate flow control can beachieved by just controlling the opening of the swinging plate, a cheapflow control valve for ore fines can be provided that is capable ofperforming stable flow control of ore fines.

Since the support portion, which is the swinging center of the swingingplate, is located above the lower end opening of the ore fines inletpipe, no sliding portions are brought into contact with the ore finesand there is no possibility of the ore fines entering between slidingfaces.

Furthermore, when means for opening and closing the swinging plate thatcloses the lower end of the ore fines inlet pipe is provided on the backsurface of the swinging plate, the flow control of ore fines can beaccomplished without bringing the means for opening and closing theswinging plate into contact with the ore fines. This can provide a flowcontrol valve for ore fines in which the opening and closing means isprevented from wearing by keeping contact with the ore fines.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is view showing a first embodiment according to the presentinvention, FIG. 1(a) being a longitudinally sectional view, FIG. 1(b)being a view taken along the line A—A, and FIG. 1(c) being a view takenalong the line B—B;

FIG. 2 is a graph showing the flow characteristic of the flow controlvalve for ore fines illustrated in FIG. 1;

FIG. 3 is a longitudinally sectional view showing a second embodimentaccording to the present invention;

FIG. 4 is a longitudinally sectional view showing a third embodimentaccording to the present invention.

FIG. 5 is a longitudinally sectional view showing a flow control valvefor ore fines according to the prior art;.

FIG. 6 is a longitudinally sectional view showing another flow controlvalve for ore fines according to the prior art;.

FIG. 7 is a longitudinally sectional view showing still another flowcontrol valve for ore fines according to the prior art.

BEST MODE FOR CARRYING OUT THE INVENTION

A preferred embodiment of the present invention will be described belowwith reference to the drawings. FIG. 1 is a view showing a firstembodiment according to the present invention, FIG. 1(a) being alongitudinally sectional view, FIG. 1(b) being a view taken along theline A—A, and FIG. 1(c) being a view taken along the line B—B.

As shown in FIG. 1, in this embodiment, an ore fines inlet pipe 2 with aflange 2 a is installed on an upper part of a casing 1 whose crosssection is rectangular, and the flange 2 a is connected to an upperflange 1 a of the casing 1 with bolt 3. To a lower flange 1 b of thecasing 1 is connected an ore fines outlet pipe 4 having a flange 4 a atthe upper end thereof, the flange 4 a of the ore fines outlet pipe 4being connected to the lower flange 1 b of the casing 1 with bolt 3. Theupper part of the ore fines outlet pipe 4 is rectangular, and the lowerpart thereof is circular.

The lower end of the ore fines inlet pipe 2 is cut to cross at aprescribed angle a to the axis center ‘c’ of the ore fines inlet pipe 2.In this embodiment, the crossed axes angle is about 60 degrees.

In this embodiment, a swinging plate 5, which keeps contact with thelower end of the ore fines inlet pipe 2, makes an acute angle with theaxis center of the ore fines inlet pipe 2, and the swinging plate 5 issupported at its upper end with a shaft 5 a rotatably attached to thecasing 1 so that the support portion is positioned above the lower endopening of the ore fines inlet pipe 2. The other end, that is, the freeend of the swinging plate 5 is thus made swingable about the shaft 5 a.

As described above, the lower end of the ore fines inlet pipe 2 is cutat a prescribed angle, and the swinging plate 5 keeping contact with thelower end of the ore fines inlet pipe 2 has the free end side at thetip, allowing the ore fines contained in the ore fines inlet pipe 2 toalways flow out from the free end side of the swinging plate 5.

A bracket 6 is attached to the back surface of the swinging plate 5, anda link member 7 is connected to the bracket 6. The link member 7 isdriven by a drive motor 10 which is connected via a drive shaft 8, whichis supported by a bracket 1 c attached to the casing 1, and a reductiongears 9. By controlling the rotation angle of the drive motor 10, theswinging plate 5 can be opened up to a desired angle. In thisembodiment, the drive motor 10 as a means for opening and closing theswinging plate 5 is installed on one side of the casing 1 to drive thelink member 7 connected to the back surface of the swinging plate 5.Reference character ‘S’ designates a seal member for the drive shaft 8installed on the casing 1.

An edge plate 11 of prescribed height is provided around three sidesexcept the free end side of the surface of the swinging plate 5 whichkeeps contact with the ore fines inlet pipe 2. It is preferable that theheight δ of the edge plate 11 would be determined in such a manner that,as shown in FIG. 1(b), the sectional area of the free end openingsection ‘e’ defined by the swinging plate 5 and the edge plate 11 onboth sides thereof becomes equal to or larger than the inner crosssectional area of the ore fines inlet pipe 2. That is, the constructionis such as, during the process of opening the swinging plate 5, theheight of the elongated rectangular opening section ‘e’ defined by theswinging plate 5 and the edge plate 11 on both sides thereof increasesand, when the line joining the upper edges of the free end side of theedge plate 11 is going to leave the lower end of the ore fines inletpipe 2, the sectional area of the opening section ‘e’ becomes equal toor larger than the inner cross sectional area of the ore fines inletpipe 2. This is because the maximum flow rate of ore fines cannot exceedthe flow rate determined by the inner cross sectional area of the orefines inlet pipe 2 and also, after the sectional area of the openingsection ‘e’ exceeds the inner cross sectional area of the ore finesinlet pipe 2, it is possible to measure the flow rate of ore fines evenif the ore fines flow out over the edge plate 11 provided on theswinging plate 5. By setting the height δ of the edge plate 11 in thisway, it can be performed to stably control the flow rate of ore finesflowing through the entire inner cross section of the ore fines inletpipe 2.

This flow control valve for ore fines V1 is installed such as the entireconstruction is tilted at a prescribed angle greater than the angle ofrepose of the ore fines. In this embodiment, the valve V1 is held at atilt angle of at about 60 degrees. This tilt ensures that the ore finesflow at a steady velocity. The tilt angle should be determined accordingto the kind of fines or the like.

According to the above flow control valve for ore fines V1 of the firstembodiment, the drive motor 10 is driven to rotate the drive shaft 8which in turn drives the link member 7 to open the swinging plate 5 upto the desired angle.

When the rotation is such as the opening height is smaller than theheight of the edge plate 11, the flow of ore fines is restricted by theedge plate 11 attached to the swinging plate 5, allowing the ore finescontained in the ore fines inlet pipe 2 to flow only through the openingsection ‘e’ at the free end side of the swinging plate 5, thusaccomplishing an accurate flow control of ore fines. In this case, therelationship between the angle of opening of the swinging plate 5 andthe flow rate of ore fines is substantially proportional as shown in thegraph of FIG. 2 showing the flow characteristic, and the stable flowcontrol of ore fines can thus be achieved.

FIG. 3 is a longitudinally sectional view showing a second embodiment ofthe flow control valve for ore fines. The second embodiment uses ahydraulic cylinder as the driving means for opening and closing theswinging plate. The same parts as those in the foregoing firstembodiment are designated by the same reference numerals, andexplanatory descriptions of such parts will be omitted here.

As shown in FIG. 3, in the second embodiment also, the ore fines inletpipe 2 with the flange 2 a is installed on the upper part of a casing 12whose cross section is rectangular, and the flange 2 a is connected toan upper flange 12 a of the casing 12 with bolt 3. In this embodiment,an ore fines outlet pipe 13 is directly fixed to the lower part of thecasing 12. The lower end of the ore fines inlet pipe 2 is cut to crossat an angle of about 60 degree to the axis center ‘c’ similarly as inthe foregoing first embodiment.

In this embodiment also, a swinging plate 14, which keeps contact withthe lower end of the ore fines inlet pipe 2, makes an acute angle withthe axis center of the ore fines inlet pipe 2, and the swinging plate 14is supported at its upper end with a shaft 14 a rotatably attached tothe casing 12 so that the support portion is positioned above the lowerend opening of the ore fines inlet pipe 2. The free end of the swingingplate 14 is thus made swingable about the shaft 14 a.

This flow control valve for ore fines V2 is installed such as the entireconstruction is tilted at a prescribed angle greater than the angle ofrepose of the ore fines. In this embodiment, the valve V2 is held at atilt angle of about 45 degrees.

The driving means for opening and closing the swinging plate 14 isattached to the back surface of the swinging plate 14. The driving meanscomprises a guide rail 15 of L-shaped section fixed to the swingingplate 14, a guide wheel 16 which moves while keeping contact with theswinging plate 14 by being guided along the L-shaped section of theguide rail 15, a triangular support member 17 which supports the guidewheel 16, an actuating shaft 18 whose one end is rotatably connected tothe support member 17, and a hydraulic or pneumatic cylinder 19 whichexpands and contracts the actuating shaft 18. Reference character ‘S’designates the seal member for the actuating shaft 18 installed on thecasing 12.

Accordingly, by controlling the amount of expansion and contraction ofthe hydraulic or pneumatic cylinder 19, the swinging plate 14 can beopened up to the desired angle.

In this embodiment also, the lower end of the ore fines inlet pipe 2 iscut at a prescribed angle, and the swinging plate 14 keeping contactwith the lower end of the ore fines inlet pipe has the free end side atthe tip, allowing the ore fines contained in the ore fines inlet pipe 2to always flow out from the free end side of the swinging plate 14. Theedge plate 11 attached around the three sides except the free end sideof the swinging plate 14 is the same as that disclosed in the foregoingfirst embodiment, and therefore, an explanatory description thereof willnot be repeated here.

According to the flow control valve for ore fines V2 of the secondembodiment, the hydraulic or pneumatic cylinder 19 is operated to expandor contract the actuating shaft 18, which causes the guide wheel 16 tomove along the guide rail 15, thereby opening the swinging plate 14 upto the desired angle.

At this time, the position at which the guide wheel 16 keeps contactwith the swinging plate 14 subjected to swing about its upper end,changes according to the angle of opening, but the guide wheel 16 canaccommodate to the displacement since it is movable along the guide rail15. The function of the edge plate 11 provided on the swinging plate 14is the same as that described in the foregoing first embodiment, andtherefore, an explanatory description thereof will not be repeated here.

FIG. 4 is a longitudinally sectional view showing a third embodiment ofthe flow control valve for ore fines. The construction of the thirdembodiment is the same as that of the foregoing second embodiment, theonly difference being in the driving means. In the third embodiment, adrive motor and a chain are used as the driving means for opening andclosing the swinging plate. The same parts as those in the foregoingsecond embodiment are designated by the same reference numerals, andexplanatory descriptions of such parts will be omitted here.

As shown in FIG. 4, in the third embodiment, the driving means forcausing the swinging plate 14 to swing comprises an actuating shaft 20whose one end is rotatably connected to the triangular support member 17that supports the guide wheel 16 provided on the back surface of theswinging plate 14, a sprocket 2 1 which engages with a threaded portion20 a formed at the other end of the actuating shaft 20, a chain 22 fordriving the sprocket 21, and a drive motor 23 for driving the chain 22.The sprocket 21 is supported by means of a support member not shown.

According to the flow control valve for ore fines V3 of the thirdembodiment, when the sprocket 21 is rotated by the chain 22 by drivingthe drive motor 23 in a controlled manner, the actuating shaft 20, whosethreaded portion 2 0 a is engaged with the rotating sprocket 21, iscaused to move left or right in the FIG. 4, so that the swinging plate14 can be opened up to the desired angle. In the third embodiment,similarly as in the first and second embodiments, since the edge plate11 provided around the three sides except the free end side of theswinging plate 14 allows the ore fines contained in the ore fines inletpipe 2 to flow out only from the free end side of the swinging plate 14,stable flow control of ore fines can be achieved.

The driving means for opening and closing the swinging plate 5 or 14 inthe first to third embodiments is not limited to the illustratedexamples, and other constructions such as one that opens and closes theswinging plate from one side of the casing 1 or 12 may be employed.

Furthermore, the tilt angle of the ore fines inlet pipe 2 described inthe respective embodiments is not limited to the illustrated examples,but the tilt angle should be determined suitably and appropriatelyaccording to the kind of ore fines, temperature, pressure or the like.

INDUSTRIAL APPLICABILITY

The flow control valve for ore fines in accordance with the presentinvention is useful for controlling a flow rate of ore fines flowingfrom an upper part to a lower part of a pipe line. Especially, this flowcontrol valve for ore fines is suitably used for controlling the flowrate of ore fines under a high temperature and a high pressure.

1 . . . casing, 2 . . . ore fines inlet pipe, 3 . . . bolt, 4 . . . orefines outlet pipe, 5 . . . swinging plate, 6 . . . bracket, 7 . . . linkmember, 8 . . . drive shaft, 9 . . . reduction gears, 10 . . . drivemotor, 11 . . . edge plate, 12 . . . casing, 13 . . . ore fines outletpipe, 14 . . . swinging plate, 15 . . . guide rail, 16 . . . guidewheel, 17 . . . support member, 18 . . . actuating shaft, 19 . . .hydraulic or pneumatic cylinder, 20 . . . actuating shaft, 21 . . .sprocket, 22 . . . chain, 23 . . . drive motor, c . . . axis center, s .. . seal member, e . . . opening section, δ. . . height, V₁, V₂, V₃ . .. flow control valve for ore fines.

What is claimed is:
 1. A flow control valve for ore fines comprising anore fines inlet pipe whose lower end is cut at a prescribed angle and aswinging plate installed in swingable fashion to control the flow rateof ore fines by controlling the opening degree between the swingingplate and the lower end of the ore fines inlet pipe, wherein the orefines inlet pipe is installed with its axis center tilted at an anglegreater than the angle of repose of the ore fines, the swinging plate,when it keeps contact with the lower end of the ore fines inlet pipe,makes an acute angle with the axis center of the ore fines inlet pipeand the swinging plate is supported at an upper end thereof so that thesupport portion is positioned above the lower end opening of the orefines inlet pipe, and an edge plate of prescribed height is providedaround three sides except a free end side of the surface of the swingingplate which closes the lower end of the ore fines inlet pipe.
 2. Theflow control valve for ore fines of claim 1, wherein means for varyingthe opening degree of the swinging plate that can close the lower end ofthe ore fines inlet pipe is provided on the back surface of the swingingplate and is driven in such a manner as to control the swinging plate.